//https://leetcode.cn/problems/longest-palindromic-substring/submissions/564202175/

class Solution {
public:
    string longestPalindrome(string s) {
        int n = s.size();

        vector<vector<bool>> dp(n, vector<bool>(n));
        int len = 1, begin = 0;

        for (int i = n - 1; i >= 0; i--)
        {
            for (int j = i; j < n; j++)
            {
                if (s[i] == s[j])
                {
                    dp[i][j] = i + 1 < j ? dp[i + 1][j - 1] : true;
                }

                if (dp[i][j] && j - i + 1 > len)
                {
                    len = j - i + 1;
                    begin = i;

                }
            }
        }

        return s.substr(begin, len);

    }
};